POSTNATAL MATURATION OF CARDIOVASCULAR REGULATORY SYSTEM

心血管调节功能出生后发育的时间进程 目前正在对1天至3个月龄以下的仔猪进行机理研究， 从监管体系流出的角度来看。因为 心血管和呼吸系统之间的密切关系 控制系统，制定产后调节的方面 后一种系统也在研究中。目前有三个具体目标 追踪：1)交感神经活动与年龄相关的差异(两者都是传出的 放电和血浆儿茶酚胺水平)，2)特征 心脏自主神经调节的发展(心脏录音 迷走神经运动神经元及HRP技术定位心交感神经 神经节后胞体)，3)呼吸节律的年龄相关变化 发生器(各种强迫输入的影响，例如，肺充气， 化学感受器刺激)。录音将从阿尔辛获得 麻醉或去大脑未麻醉的仔猪：传出 交感神经活动(内脏、颈交感、肾)，传出 疑核内的膈神经放电、心脏迷走神经纤维、运动神经元 腹外侧核、主动脉压、EKG、区域动脉 血流(特别是肾脏、肠系膜)和适当的标记 脉搏。神经传入放电改变对年龄的影响 各种心血管-呼吸感受器，例如心肺， 中枢心血管和呼吸上的动脉压力感受器 将对控制系统进行评估。《同情心》中的常见周期 与心动周期有关的放电和周期(由EKG表示) 或中枢呼吸周期(以传出膈神经放电表示) 通过互相关和功率谱分析揭示， 特别是功率谱等价性和相干性的测试。这个 脑刺激和高碳酸血症、低氧等应激的影响 出血也将被评估。结果的年龄相关性将是 对6个日龄的仔猪进行了统计测定。结果将会是 有助于我们理解宫外循环调节 环境和据我们所知的监管程度 新生儿具有心血管功能。信息将会是 获得的信息，这对于理解 对各种压力(高碳酸血症、出血、 低氧)，尤其与生命中最脆弱的时期有关 那个孩子。

The time course of postnatal development of cardiovascular regulatory mechanisms is being studied in piglets Less than 1 day-3 months of age, from the viewpoint of efferent out-flow of the regulatory system. Because of the close interrelationship between the cardiovascular and respiratory controlling systems, aspects of developing postnatal regulation of the latter system are also being studied. Three specific aims are being pursued: 1) age-related differences in sympathetic activity (both efferent discharge and plasma catecholamine levels), 2) characteristics of development of autonomic regulation of the heart (recordings from cardiac vagal motoneurons and use of HRP techniques to locate cardiac sympathetic postganglionic soma), 3) age-related changes in the respiratory rhythm generator (efects of various forcing inputs, e.g., lung inflation, chemoreceptor stimulation). Recordings will be obtained from Althesin anesthetized or decerebrate unanesthetized piglets of: efferent sympathetic activity (splanchnic, cervical sympathetic, renal), efferent phrenic discharge, cardiac vagal fibers, motoneurons in nucleurs ambiguus and ventrolateral nucleus ambiguus, aortic pressure, EKG, regional arterial blood flow (particularly renal, mesenteric) and appropriate marking pulses. The age-related effects of alterations in afferent discharge from various cardiovascular-respiratory receptors, e.g. cardiopulmonary, arterial baroreceptors, on central cardiovascular and respiratory controlling systems will be evaluated. Common periodicities in sympathetic discharge and periodicities related to the cardiac cycle (indicated by EKG) or central respiratory cycle (indicated by efferent phrenic discharge) are being revealed by cross correlation and power spectral analyses, particularly tests for power spectral equivalence and coherence. The effects of brain stimulation and of stresses such as hypercapnia, hypoxia and hemorrhage will also be evaluated. Age-dependency of results will be determined statistically in 6 age groups of piglets. The results will contribute to our understanding of circulatory adjustments to extrauterine environment and to our knowledge of the degree of regulation of cardiovascular function available in the neonate. Information will be obtained which is necessary for the understanding of reflexes involved in physiological adjustments to various stresses (hypercapnia, hemorrhage, hypoxia), relevant especially to the most vulnerable period in the life of the child.